Radio Physics and Radio Astronomy (Jun 2019)
CREATING THE RT-32 RADIO TELESCOPE ON THE BASIC OF MARK-4B ANTENNA SYSTEM. 1. MODERNIZATION PROJECT AND FIRST RESULTS
Abstract
Purpose: Creating a radio telescope based on the MARK-4B antenna system being developed for telecommunication applications, determining the possibilities of using the broadband multirange operation of a beam wave-guided antenna system and to evaluate the antenna characteristics using the radioastronomical measurements. Design/methodology/approach: Acomprehensive analysis of all the MARK-4B systems allows to select the blocks and nodes to be replaced or upgraded. The analysis of the reflector and subreflector design, beam wave-guide, corrugated horn, and feeder system allows determining the possible frequency ranges of the radio telescope being created. Installing a broadband receiver with the stipulated calibration capabilities using cooled and uncooled load attenuators allows to determine the antenna system temperature. Guiding the antenna to the calibration sources and recording scans due to the Earth rotation eliminates the systematic errors or errors of the pointing system. In this way the width of the radiation pattern and the effective area of the radio telescope are determined. Findings: An analysis of the antenna design was made and the priority stages of the reconstruction of the MARK-4B antenna system were determined. The narrow-band transmitter and the C-band receiver were dismantled and a wide-band receiver (range 4.6 - 5.1 GHz) with a detector and the possibility of changing the signal integration time were installed. The observed results have allowed to initially estimate the system temperature mea-surements which allow us to hope that the RT-32 radio telescope (Zolotchiv, Lviv region, Ukraine) together with the cooled receiver will have low self noise. A new antenna pointing system has been calculated and installed which using in the C-band has allowed astronomical tests of the radiation pattern width (≈7.2') and the level of its side lobes (–12.5 dB), effective area (≈680 m2) and surface utilization factor (≈0.84). Conclusions: The completed measurements and calculations show that the MARK-4B antenna system allows to createhighly efficient radio astronomy instrument. The developed for now receiving and pointing systems for the RT-32 radio telescope testify to the high potential of Ukrainian science. Further cooperation between scientific research and high technologies will lead to the creation of an effective Ukrainian radio telescope of the centimeter wavelength range.
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